Chapter 1: The Scientific Study of Life
Chapter 1 Learning Objectives:
€ Describe the characteristics that all living organisms share
€ Give an example of each level of biological organization
€ Compare and contrast the three domains of life
€ Compare and contrast the four major groups of eukaryotes
€ Apply the scientific method to design experiments and analyze data
€ Identify the variables in an experiment
€ Differentiate between hypotheses and theories
€ List some of the limitations of the scientific method
1.1 What is life?
1. Life is organized
2. Life Requires Energy
3. Life Maintains Internal Constancy
4. Life Reproduces Itself, Grows, and Develops
5. Life evolves
A. Life is organized:
List the levels of life's organization and recognize examples or characteristics of
each. Be able to arrange the levels of life’s organization from simplest to most
complex.
1. Atom: The smallest chemical unit of an element
2. Molecule: A group of joined atoms (Example: DNA)
3. Organelle: A membrane-bounded structure that has a specific function within a
cell
4. Cell: A unit of life. Multicellular organisms consist of many cells; unicellular
organisms consist of only one cell
5. Tissues: A collection of specialized cells that function in a coordinated fashion.
6. Organ: A structure consisting of tissues organized to carry out specific functions.
7. Organ System: Organs that are connected physically or chemically that function
, together
8. Organism: A single living individual
9. Population: A group of the same species of organisms living together in the same
place and time
10. Community: All populations that occupy the same region
11. Ecosystem: The living and non-living components of an area
12. Biosphere: The global ecosystem the parts of the planet and its atmosphere
where life is possible
Which of the levels listed above is considered the smallest unit of life? Cells are
considered the smallest unit of life
Which levels are found only in multicellular organisms? Tissues, Organ, Organ
System
Characteristics of a system that do not appear in any of its components are called
emergent properties.
Emergent properties: are new functions that arise from physical and chemical
interactions among a system’s components, much as flour, sugar, butter, and chocolate
can become brownies—something not evident from the parts themselves.
Name an example of an emergent property.
B. Life Requires Energy.
Organisms are classified as producers or consumers based on how they obtain energy.
● Primary Producers are also called autotrophs.
o How do producers obtain energy and nutrients? From the environment:
Sunlight is normally the energy source.
● Consumers are also called Heterotrophs.
o How do consumers obtain energy and nutrients? Consumers obtain
energy and nutrients from other organisms
o What is a decomposer? A decomposer breaks down waste or dead
organisms to release nutrients: Bacteria and Fungus
Energy flows in one direction through producers, consumers, and back to the
environment. At each transfer, energy is lost as heat.
Chapter 1 Learning Objectives:
€ Describe the characteristics that all living organisms share
€ Give an example of each level of biological organization
€ Compare and contrast the three domains of life
€ Compare and contrast the four major groups of eukaryotes
€ Apply the scientific method to design experiments and analyze data
€ Identify the variables in an experiment
€ Differentiate between hypotheses and theories
€ List some of the limitations of the scientific method
1.1 What is life?
1. Life is organized
2. Life Requires Energy
3. Life Maintains Internal Constancy
4. Life Reproduces Itself, Grows, and Develops
5. Life evolves
A. Life is organized:
List the levels of life's organization and recognize examples or characteristics of
each. Be able to arrange the levels of life’s organization from simplest to most
complex.
1. Atom: The smallest chemical unit of an element
2. Molecule: A group of joined atoms (Example: DNA)
3. Organelle: A membrane-bounded structure that has a specific function within a
cell
4. Cell: A unit of life. Multicellular organisms consist of many cells; unicellular
organisms consist of only one cell
5. Tissues: A collection of specialized cells that function in a coordinated fashion.
6. Organ: A structure consisting of tissues organized to carry out specific functions.
7. Organ System: Organs that are connected physically or chemically that function
, together
8. Organism: A single living individual
9. Population: A group of the same species of organisms living together in the same
place and time
10. Community: All populations that occupy the same region
11. Ecosystem: The living and non-living components of an area
12. Biosphere: The global ecosystem the parts of the planet and its atmosphere
where life is possible
Which of the levels listed above is considered the smallest unit of life? Cells are
considered the smallest unit of life
Which levels are found only in multicellular organisms? Tissues, Organ, Organ
System
Characteristics of a system that do not appear in any of its components are called
emergent properties.
Emergent properties: are new functions that arise from physical and chemical
interactions among a system’s components, much as flour, sugar, butter, and chocolate
can become brownies—something not evident from the parts themselves.
Name an example of an emergent property.
B. Life Requires Energy.
Organisms are classified as producers or consumers based on how they obtain energy.
● Primary Producers are also called autotrophs.
o How do producers obtain energy and nutrients? From the environment:
Sunlight is normally the energy source.
● Consumers are also called Heterotrophs.
o How do consumers obtain energy and nutrients? Consumers obtain
energy and nutrients from other organisms
o What is a decomposer? A decomposer breaks down waste or dead
organisms to release nutrients: Bacteria and Fungus
Energy flows in one direction through producers, consumers, and back to the
environment. At each transfer, energy is lost as heat.
